VR_GET32
cam_mask = VR_GET32(vrp->acc_reg, VR_CAM_MASK);
mask = VR_GET32(vrp->acc_reg, VR_CAM_MASK);
VR_PUT32(acc, r, VR_GET32(acc, r) & ~(b))
VR_PUT32(acc, r, (VR_GET32(acc, r) | (b)))
VR_PUT32(acc, r, (VR_GET32(acc, r) & ~(b)) | (v))